This is insanity
"What the hell is going on? Don't tell me this is what that guy's doing? What a sick bastard."
Beside Primo's forces, there was Dragon and that other one he assumed was Dimitri's henchman. These dead people in the hallway were Dragon's men, for sure. Therefore, Primo assumed this was Dimitri's people doing. Primo continued his journey to get to the other end of the hallway, but when he turned, the scene was the same as the previous one.
"This… is insanity."
As a felon and villainous himself, Primo knew that killing someone with a gun was the most efficient way. But for someone to use their hands and wield a knife or anything the like, only displayed the level of craziness and confidence the perpetrator was. Considering the circumstances, wielding a close-combat weapon was a lot riskier. Thus, the mere thought of it made the hairs on the back of his neck raise.
Whoever did this was a skilled monster. The worst of all.